hp Color 9850mfp SCANNER C. APS detection timing (scanner mode) The original size in the main scan direction is detected twice. The larger size is regarded as the original size. II UNIT EXPLANATION [1] 1st original size detection [2] 2nd original size detection (main scan direction, sub-scan direction) (main scan direction) 2-9 [1] [2] APS sensor S (PS3) APS sensor L (PS4) Exposure lamp (L1) APS timing sensor (PS2) DF reset read switch (RS1)